Comparison of thermal, plasma-enhanced and layer by layer Ar plasma treatment atomic layer deposition of Tin oxide thin films

Abstract

In this work, Tin oxide (SnOx) thin films have been prepared by different atomic layer deposition (ALD) methods, namely thermal (T-ALD), plasma enhanced (PE-ALD) and subsequent layer by layer Ar plasma treatment (PE-ALD-ALT) modes. In the thermal plasma mode, ozone acts as the oxygen source and Tetrakis(dimethylamino)tin (TDMASn) provides the metal cation. In the plasma-enhanced mode, oxygen plasma was used as the oxygen source. For comparison, we added an Ar plasma treatment step after each layer deposition in the plasma enhanced ALD mode. Compared to T-ALD, the reaction process with O2 plasma as the oxygen source obtained higher growth per cycle (GPC) and crystallinity as well as higher carrier mobility. layer by layer Ar treatment further increased the film carrier concentration and decreased the film resistivity, which also inevitably caused a further increase in the roughness and residual stress in the film.